Photographically dye-printed fabrics and method of making same



Sept. 10, 1940. Q. R. FLYNN ETAL. 2,214,365

PHOTOGRAPHICALLY DYE-PRINTED FABRICS AND METHOD OF MAKING SAME Filed June 18, 1938 ZSmaentor v attorney Patented Sept.-10, 1940 V UNITED STATES, PATENT OFFICE rnoroommomr nm-ramrsp ranmcs AND METHOD or mnvc same Oscar Rogers Flynn, .East Orange, and Francis Stillman Richardson, Rutherford. N. 1., assignors to Waldrich Company, Delawanna. N. L, a corporation of-New Jersey application June is. 193s, Serial No. 214,528 z Claims. (01. 95-6) able medium, there is produced on the fabric a photographically printed design, pattern or picture corresponding to that of the negative. The photograph thus printed on the fabric is fast to light and is insoluble in water, while the dye of the fabric which has not been subjected to light through the negative in the printing process is readily soluble in water and can be removed from the fabric by simple washing operations. In accordance with this process, it is unnecessary to fix the photographically printed areas of the dyed fabric other than by inerely exposing the.

dyed fabric to the action of light through the negative in the step of photographically printing the dyed fabric. While on the other hand, as stated, the dye which has not been acted upon by the light is readily washed out by a simplewashing'operation. The production of a photograpically printed fabric thus fast to light constitutes one of the-objects of the present invention.

Another object of the invention is the provision of a photographic method of dye printing which can be performed while the dyed fabric is wet or dry and which preferably can also be pergraph reproduced on the fabric when the-dyed fabric is exposed to light throughthe negative is permanent and of such character that subse- 1 quent treatment of the fabric for the purpose of removing the unaffected dye does not in any way impair the printed portion of the fabric, thereby eliminating one of the objections of prior meth- 65 ods according to which the light treated por- Accordingly, when being preferred. The leuco ester compounds are tions of the dyed fabric mustbe specially fixed with the result that the photograph on the fabric is liableto be impaired during the mechanical handlingof the printed fabric in the course of fixing the light treated dye, in the'course of 6 removing the untreated dye, etc.

A yet further object of the invention is generally to provide an improved photographically printed fabric and the method of dye-printing I fabrics by the photographic process. 10

The above objects of the invention and other objects which might hereinafter appear will be fully understood from the following description,

reference being bad to the accompanying drawing which illustrates the preferred manner of performing the method of the present invention.

In the drawing:

Fig. 1 is a more or less diagrammatic end view of apparatus utilized in performing the method 26 of the present invention.

Fig. 2 is a view similar to Fig. 1 illustrating the use of a larger negative.

In performing the method in accordance with the present invention for photographically dye printing the fabric, the latter, after being freed from all foreign matter, such as dust, starch, or size, is impregnated with the dye. In other words, before dyeing the fabric, care is taken to condition the same by the removal of foreign materials which would interfere with the contact of the dye witl'i the fibers of the-fabric. The dyes which are utilized are normally soluble in water and are rendered insoluble by being subjected to the action of light Dyes having this 35'- property and which in other respects are particularly suitable for. accomplishing the objects of the present invention are the esters of the leuco compounds of vatdyes, the'salts of the esters of the leuco compounds of the vat dyes preferably the dyes designated by the trademark Indigosols' and are readily available on the market in a wide range of colors. For preparing the light sensitive dye solution the dye, 45

that is the salt of the esterof the leuco compound of the vat dye is' dissolved in water in the portion of about twenty grams of dye in one liter of water, the temperature of-the water being at about F. For the color brown,

-warmer water is used, specifically water at a neither of these acids is recommended because in the case of sulfuric acid the fiber of the fabric might be impaired, while in the case of acetic acid, there is a tendency to stain the fabric. It has been found that the addition of the preferred acid, that is formic acid, in the above mentioned quantity accelerates the action of the light on the dye for rendering the latter insoluble, but except in the case of a .color where the action of light is relatively slow, it is unnecessary to use the accelerator as excellent results have been obtained without the same. In some instances we have found that the use of 'hygroscopic agents such as glycerine and particularly urea have a favorable accelerating influence.

The fabric, in dry condition and with all such foreign materials which would interfere with the subjected to treatment in the photographic printing frame. Accordingly, after the fabric is impregnated with the dye by immersing the fabric in the dye solution, excess dye is removed in any suitable way, preferably by passing the fabric between quetch rolls so that the fabric is as moist as possible but is just short of dripping wet.

After being thus impregnated with the dye, the fabric is rolled up without exposure to strong light and thereafter, preferably while the fabric is still moist, is fed through the photographic printing machine for exposing the fabric to the action of light in the presence of 'air through the photographic negative or through a' film carrying the desired photograph or design which is to be produced on the fabric. The fabric when thus exposed to light is preferably in the moist condition described above as just short of dripping wet, although the fabric may be less moist or even dry.

Referring now to Fig. l of the drawing, the method'performed in accordance with the present invention for photographically printing the dyed fabric will now be described. The printing frame used in performing the present method is indicated generally by the reference numeral ill. Said frame comprises a rotary transparent cylinder I2 of glass or other suitable material within which there is positioned a suitably strong light It. The photographic negative or design carrying film i6 is mounted on the outer surface of cylinder i2 in fixed relation thereto and rotates with said cylinder about light source M. The roll i8 of dye impregnated fabric carried by spindle. 20 is supported for rotation at its oppo-- site ends in arms 2i, one at each end of the supporting rack 22. The fabric is supplied from roll I8 to the printing frame it and more particularly is brought into contact with the outer surface of the negative l6 mounted on the glass cylinder, being held in contact with said glass cylinder by suitable: presser members (not shown) conventionally used in printing frames. The fabric thus disposed around the negative I6 is subjected to the action of light which passes The dye impregnated through the latter with the result that the dye which is acted upon by the light is rendered insoluble. The printed fabric is then wound on take-up roll 24 on a spindle 26 mounted for rotation at its ends in arms 28, one at each end 'of rack 22.

Spindle 26 is preferably positively driven at the same speed of rotation as cylinder l2. For this purpose, said spindle is provided desired. ,A speed of one foot per minute, on the average, has been found satisfactory for all colors where there was utilized in the printing frame eight are lamps spaced uniformly longitudinally within the glasscylinder of the printing frame and operating on 230 volts with each lamp consuming about five amperes. In the printing frame referred to the length of cylinder I2 is fifty-four inches. As the fabric is preferably in a moist condition when passed through the printing frame in contact with negative IS, the latter has applied thereto on both surfaces thereof a waterproof coating. For this purpose, a suitable waterproof varnish is utilized. A suitable varnish is available on the market under the trade name I-Iilo varnish C". In lieu of a waterproof varnish or coating, a transparent waterproof film or sheet may be interposed between.

the negative and the fabric.

As illustrated in Fig. 2 of the drawing, provision is made for utilizing a negative lBa. which is considerably larger than the negative l6 hereinbefore mentioned. This largernegative may be necessary when the photograph or the repeat unit of the design or pattern to be printed on the fabric is large, while the smaller negative it which ismounted directly upon the glass cyl-' inder' l2 will ordinarily be sufficient for relatively smaller photographs or for relatively small repeat units of the design. The larger negative Ilia, instead of being mounted directly on cylinder i2 is, as here shown, in the form of an endless belt which engages glass cylinder i2 and a roller 36 mounted at its ends for rotation in arms 38 carried by rack 22. As the length of the negative I6a,may vary, arms 38 and roller 36 carried I thereby are adjustable toward and away from cylinder 12. For this purpose each of the said arms is provided with a longitudinally extending slot 40 engageable with adjusting screws 42 for releasably fixing said arms in the desired posi tion. As the same rack 22 may be used either when the negative is mounted directly on the cylinder or when the negative is in the form of a belt or loop, the roller 36 is also illustrated in Fig. l of the drawing, but in the apparatus there illustrated said roller is not in use.

It will be understood that in the operation of the apparatus in accordance with the method of washed in soapy water at about the same temperature until the unexposed dye has beenremoved and rinsed in clear water. To make sure that all of the unexposed dye has been removed by the washing operation, a piece of fabric maybe tested by exposure to light. If the exposure to light produces no change in the color of the portion or the fabric thus tested, the complete removal of the surplus dye is indicated.

In general, all fabrics, smooth or pile and including paper or other fibrous sheet material may 'be photographically dye printed in accordance with the present invention. It has been found,

however, that in the case of wool the dye attaches itself to the fiber and, even though unexposed to light, resists removal by water or soapy water as hereinbefore described. This resistance to the removal of the dye also applies to pure silk but unlike wool, pure silk can be treated with an alkali for removing the dye, that is the dye not made insoluble in water by the action of the light on the fabric in the printing frame, without impairing the fibers. The process of this invention is particularly advantageous in respect to silk, rayon, cotton and linen fabrics and more generally to all fabrics having fibers derived from cellulose.

Thus it is seen that the photographically dyed printed fabric and the method of making the same as hereinbefore described are well adapted to accomplish the several objects of the present invention. It is to be noted that the utilization for the purposes of the present invention of a dye of the properties referred to, thatis, dye which is rendered water insoluble by the action of light gives rise to several important advantages. More particularly, it is to be observed that since. the exposed dye is water' insoluble, the fabric after being passed through the printing frame can be wound on a roll and otherwise handled without danger of impairing the'reproduced design on the fabric, it being unnecessary to take the precautions heretofore required in connection with the photographic printing of fabrics in which it wasnecessary to fix the dye after the exposure thereof to light. In accordance with the present invention it is not only unnecessary to fix the dye after the latter have been exposed to light in the printing thereof, but the printed fabric can be handled in such a manner as to facilitate the production thereof and to simplify the manufacturing operations. It will be observed also that one of the advantages of the present invention is that it makes possible the continuous process, with the dyed fabric either in wet or dry condition, and enables a continuous printingor the application of repeat unit of a design on successive portions of a length of fabric as in ordinary engraved roller printing. It will be understood also that the present method not only eliminates the danger of impairing the printed design or photograph PIiOl' to the eliminates the necessity for the utilization of I special fixing fabric with an ester of fixing of the latter, but also' and developing chemicals which are required in other photograph dye printing processes.'

In accordance with may be treated continuously from the state in which it is dry, prior to cleansing and dyeing, to the finished state in which the dye-printed fabric is washed and dried. Thus, the fabric may betreated progressively and in sequence, one step following the other in a continuous manner, for (1) removing the foreign matter to condition the fibers of the fabric to receive the dye, (2) the dyeingof the fabric, (3) the exposure of the dyed fabric to light in the printing frame, and (4) the washing of the dye-printed fabric to remove the unchanged dye. Accordingly, the dyed fabric may be fed directly from the dyeing vat, preferably between quetch rolls, to the printing frame, it being unnecessary to wind the dyed fabric on a supply roll although this is preferred.

' v While we have disclosed the preferred embodiment of our invention and the preferred manner of practising thesame, it will be understood that the invention is susceptible of certain modifications, changes and additions. Thus, instead of immersing the fabric in the dye, the latter may be applied by a roller carrying the desired design, as in ordinary printing, and thereafter the fabric is passed through the printing frame. It will be understood further that multi-colored effects may be obtainedon the same fabric by not wish to be limited precisely to the'embodiments of the invention herein illustrated or de-- scribed except as may be required by the appended claims.

Having thus described our. invention, what we claim and desire to secure by Letters Patent is:

1. The method of photographically dye-printing fabrics of indefinite length with a repeat unit positioned on successive portions of the fabric, which method comprises impregnating said length of fabric with an ester of a leuco compound of a vat dye in a solution containing formic acid, then progressively exposing successive portions of said fabric to the. action of light through a negative carrying said repeat unit, and thereafter washing out from the fabric the dye which has not been exposed to the light for making the same insoluble.

2. The method of photographically dye-printing fabrics, which comprises impregnating the a leuco compound of a vat dye in a solution containing formic acid, then exposing the fabric and thereafter washing out from the fabric'the leuco ester compound which has not been made insoluble by exposure to light.

OSCAR ROGERS FLYNN. FRANCIS S'IIILMAN'RICHARDSON.

our method, the fabric.

to light through a negative, I 

